The German newspaper Süddeutsche Zeitung, along with its two broadcast partners, NDR and WDR, reported Wednesday that police raided the home and office of an official in the German Defense Ministry who was spying for a U.S. intelligence agency. The Federal Prosecutor's office told the newspaper the search was continuing.

On July 4, we told you that authorities had arrested another man for allegedly passing secrets to the U.S. That man worked for the BND, Germany's foreign intelligence agency. He is thought to have passed information about a German parliamentary inquiry into the U.S. National Security Agency's spying on Germans.

"We have investigations in two cases of suspected espionage, a very serious suspicion," government spokesman Steffen Seibert said in Berlin.

Last week's arrest, as well as the present case, comes at a delicate time for U.S-German relations. Ties between the allies have been strained since revelations by former NSA contractor Edward Snowden that the agency spied on Germans, including Chancellor Angela Merkel. Indeed, The New York Times reports, when President Obama called Merkel on July 3 about the situation in Ukraine, he was unaware of the arrest of the German intelligence official.

"While Ms. Merkel chose not to raise the issue during the call, the fact that the president was kept in the dark about the blown spying operation at a particularly delicate moment in American relations with Germany has led frustrated White House officials to question who in the C.I.A.'s chain of command was aware of the case — and why that information did not make it to the Oval Office before the call."